Apparatus for false twist crimping synthetic fibers for producing a woollike appearance



Apnl 16, 1963 H, WEGENER ET AL 3,085,389

APPARATUS FOR FALSE TWIST CRIMPING SYNTHETIC FIBERS FOR PRODUCING A WOOL-LIKE APPEARANCE Filed Aug. 11, 1954 2 Sheets-Sheet l INVENTOR$ Hurry WegenerX ATTORNEY Aprll 16, 1963 H. WEGENER ET AL 3,085,389

APPARATUS FOR FALSE TWIST CRIMPING SYNTHETIC FIBERS FOR PRODUCING A WOOL-LIKE APPEARANCE Filed Aug. 11, 1954 2 Sheets-Sheet 2 l 2 S E? LL.

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INVENTORS 6 BY r/mmq ky lfifi ATTORNEY United States atent O APPARATUS FOR FALSE TWIST CRIMPING SYN- THETIC FIBERS FOR PRODUCING A WOOL- LIKE APPEARANCE Harry Wegener, Chur, Graubunden, and Heinrich Keller, Ems, Graubunden, Switzerland, assignors to Inventa A.G. fuer Forschung und Patentverwertung, Zurich, Switzerland Filed Aug. 11, 1954, Ser. No. 449,097 Claims priority, application Switzerland Aug. 12, 1953 2 Claims. (Cl. 57-34) The present invention relates to the treatment of synthetic fibers so as to impart a crimp to the same and to cause them to resemble naturally crimped fibers such as wool and relates more particularly to processing fully synthetic materials in continuous operation.

It is well known that a wool-like crimp may be imparted to synthetic fibers by providing an untwisted or pretwisted thread with twists, the turns of which are by far higher in number than the usual number of turns. After having fixed the state of twist, for instance with the usual wet steam, the thread is turned in an inverse sense down to zero, or surpassing zero. By this procedure, the individual fibrils are'made to open with an increase in bulk and form a voluminous yarn of high resilience.

It is an inconvenience of the known process that the yarn cannot be completely finished in a continuous operation, but has to be processed in a number of steps, which in their entirety take up a great deal of time. A continuous process is therefore preferable because it permits one to obtain larger yields.

It is the object of the present invention to overcome the above-mentioned drawbacks and provide means and a process for producing crirnped yarns in a continuous operation.

According to the invention, a thread is given a so-called false twist by means of a particularly devised twisting member. A very important factor determining the success of the process is the thoroughness of fixation of the twist after the first phase of the operation. It has been found that such fixation can be effected successfully by making the highly-twisted thread pass continuously through a heating device in either unswelled or swelled state, so that the moistening or swelling agent, e.g. water will evaporate during said passage through the heating device. In this way, a faster and deeper-reaching heating of the fiber is obtained.

Furthermore, the steam generated in this way cannot immediately escape from the interior because the thread is tightly twisted. As a consequence, higher steam pressures and temperatures will develop momentarily in the interior of the thread-forming bundle of fibrils than in its environment. The fixation of the twist imparted to the thread will therefore occur in a much shorter time than with the conventional methods, in which steam has to penetrate from the outside through a wound thread; in some cases the bobbin in the steam chamber has first to be evacuated to make it possible for the steam effectively to reach the innermost layers of the bobbin. This explains the long periods of steaming of bobbins in the steam chamber in conventional operations used heretofore.

The device according to the invention will now be explained with reference to the accompanying drawing, but it should be understood that these are given by way of illustration and not of limitation and that many changes can be made without departing from the spirit of the invention.

FIG. 1 shows diagrammatically an arrangement for the production of crimped thread from moist yarn;

FIG. 2 shows a similar arrangement wherein the moistening of the yarn occurs at a later stage;

FIG. 3 is another similar arrangement, in which the moistening occurs by different means;

FIG. 4 shows the device for imparting the so-called false twist to the thread;

FIGS. 5 and 6 show another embodiment of the false twist-imparting device in longitudinal section and in plan view, respectively; and

FIG. 7 shows a further embodiment of that device.

FIG. 8 is a bottom view of the same embodiment as shown in FIG. 7.

According to FIG. 1, the fully stretched and slightly pretwisted thread T consisting of entirely synthetic material in moist state (moisture contents 1020%) is wound on a bobbin -1a and placed on shaft 1. From there, the thread is fed to a pair of feed rollers 2, passed through a heater 3 to a false-twist imparting device 4 and from there to another pair of rollers 5. These rollers deliver the thread to a bobbin 7 on which it is wound up.

g and g are guide members for directing the thread as it travels from one device to the other.

It is also possible to combine or ply several threads as they leave the delivery rollers 5 and twist them on known thread producing devices into a multiple thread, in order to obtain stronger thread. Between the feed rollers 2 and the twisting device 4 the thread is twisted to at least 1500 turns per meter. In this highly twisted state, the thread passes the heating device 3 whereby it is fixed. Thereafter the thread is preferably cooled to below C., e.g. by treating the thread after leaving the heating device with cooling gases by means of a nozzle 6.

According to the arrangement shown in FIG. 2, dry yarn is used, which is first passed through a steaming chamber 2a. The moistening agent need not be pure water, but other known swelling means may also be used, for instance sulfonates \of fatty alcohols, primary alcohols, etc., also products of pre-condensation or pre-polymerization, to improve the fixation of the filament in its frizzled form, either by themselves or diluted with water.

According to FIG. 3, dry yarn is admitted, which is moistened by means of the disk 2b passed through a vessel 8 containing a swelling bath which may be heated to boiling temperature.

The heating device is heated by electrical or other known means in such a manner that the thread is heated by radiation from the hot wall, the temperature of the thread after the evaporation of moisture having reached the necessary temperature for fixation.

[In order to obtain an accurate twisting, it is necessary to maintain a certain tension on the thread between the two pairs of rollers 2 and 5, the amount of the tension being determined by the thickness of the thread, the degree of crimp, by the turns to be imparted to the thread, the tension becoming higher with increasing number of twists.

Since the reverse twisting, after the thread leaves the device 4, is preferably carried out at a higher tension, because the thread is lengthened during this operation, it is necessary to maintain the thread, between entering and leaving device 4, at two different tensions. This can be effected, in a particular embodiment of the invention, by designing the device 4 in such a manner that the thread will be subjected by a thread-braking arrangement, not shown in FIGS. 1-3, to a compmatively strong braking action during the passage therethrough, so that the tension of the thread will be increased when it leaves the device.

Difierent embodiments of the device 4, shown only schematically in FIGS. 1, 2 and 3, are shown on an enlarged scale in FIGS. 4-7.

In FIG. 4, we show a device for imparting a false twist, in the form of a rotary tube 9 with a plate 10, provided with at least one perforation 11.

The rotary tube which has a mushroom shape due to the plate at the bottom end, is a novel arrangement. The thread 12 enters from the top, passes tube 9, and is threaded through the opening 11, whereupon it leaves the device over the edge of plate 10.

The Whole system can also be turned upside-down, so that the plate lies at the top, the thread entering from the bottom, passing through the interior and leaving at the top.

The embodiment shown in FIGS. and 6 is particularly advantageous. It comprises again a rotary tube 9a and a plate 1011, which is in this case provided with a number of slots 13. The thread 12 enters tube 9a at the top, passes through the tube, emerges at the bottom, passes back to the top through one of the slots, wraps around the exterior of the tube, passes through another slot and leaves the device from there. The braking of the thread can be varied by the number of passages through the slot, in which case the thread does not always have to be Wrapped around the outside of the tube.

Finally, in the embodiment shown in FIGS. 7 and 8, a plate 14 is superposed to plate 13 which bears down on thread T performing-a braking action thereon. Plate 14 can be weighted down by helical spring 15 which bears against plate 14 with one end and against an abutment plate 16, with its other end; plate 16 is rigidly connected to tube 9a.

'It has aslo been discovered that the wool-like character of the crimped thread becomes more pronounced when the thread, after leaving the pair of nollers 5, is conveyed to further rollers, revolving at higher speed, whereby the thread is tensioned; only after leaving this last pair of rollers will the thread be finally wound on a bobbin. Between the two pairs of rollers, the thread should have a tension which exceeds that on the bobbin.

What we claim is:

1. In an apparatus for making crimped synthetic fibers of wool-like appearance having first bobbin means for winding the pretensioned and moistened thread thereon, false-twist mechanism arranged consecutively to said first bobbin means for imparting to the thread a false twist of at least 1,500 turns per meter, said mechanism comprising a thread-braking arrangement including a tube and a first plate thereon so as to give the tube the appearance of a mushroom, said first plate having at least one opening capable of receiving the thread and causing a braking of the same as it passes the edge, means for conveying the thread from said bobbin means to said false-twist mechanism, heater means arranged in the path of the thread between said bobbin means and said false-twist mechanism in timed relationship therebetween, cooling means disposed adjacent the path of the thread between said heater means and said false twist means for cooling the thread, and second bobbin means arranged consecutively to, and c'o-acting with, said false-twist mechanism for Winding the thread on the former, the improvement which comprises arranging a second plateabove said first plate, said second plate being weighted in order to brake the thread.

2. In-an apparatus as defined in claim 1, the further improvement wherein said second plate is Weighted by spring means.

References Cited in the file of this patent UNITED STATES PATENTS 1,987,449 Schweizer et a1. Jan. 8, 1935 2,089,239 Whitehead Aug. 10, 1937 2,111,209 Dreyfus Mar. 15, 1938 2,111,211 Finlayson et al. Mar. 15, 1938 2,244,832 'Finlayson et al. June 10, 1941 2,463,618 Heberlein et'al. Mar. 8, 1949 2,463,620 Heberlein Mar. 8, 1949 2,464,502 Hall et al Mar. 15, 1949 2,475,922 Stockly July 12, 1949 2,740,251 Bierlin Apr. 3, 1956 2,753,679 Von Schmoller et al. July 10, 1956 2,863,280 Ubbelohde Dec. 9, 1958 FOREIGN PATENTS 588,329 Great Britain May 20, 1947 606,257 Great Britain Aug. 11, 1948 

1. IN AN APPARATUS FOR MAKING CRIMPED SYNTHETIC FIBERS OF WOOL-LIKE APPEARANCE HAVING FIRST BOBBIN MEANS FOR WINDING THE PRETENSIONED AND MOISTENED THREAD THEREON, FALSE-TWIST MECHANISM ARRANGED CONSECUTIVELY TO SAID FIRST BOBBIN MEANS FOR IMPARTING TO THE THREAD A FALSE TWIST OF AT LEAST 1,500 TURNS PER METER, SAID MECHANISM COMPRISING A THREAD-BRAKING ARRANGEMENT INCLUDING A TUBE AND A FIRST PLATE THEREON SO AS TO GIVE THE TUBE THE APPEARANCE OF A MUSHROOM, SAID FIRST PLATE HAVING AT LEAST ONE OPENING CAPABLE OF RECEIVING THE THREAD AND CAUSING A BRAKING OF THE SAME AS IT PASSES THE EDGE, MEANS FOR CONVEYING THE THREAD FROM SAID BOBBIN MEANS TO SAID FALSE-TWIST MECHANISM, HEATER MEANS ARRANGED IN THE PATH OF THE THREAD BETWEEN SAID BOBBIN MEANS AND SAID FALSE-TWIST MECHANISM IN TIMED RELATIONSHIP THEREBETWEEN, COOLING MEANS DISPOSED ADJACENT THE PATH OF THE THREAD BETWEEN SAID HEATER MEANS AND SAID FALSE TWIST MEANS FOR COOLING THE THREAD, AND SECOND BOBBIN MEANS ARRANGED CONSECUTIVELY TO, AND CO-ACTING WITH, SAID FALSE-TWIST MECHANISM FOR WINDING THE THREAD ON THE FORMER, THE IMPROVEMENT WHICH COMPRISES ARRANGING A SECOND PLATE ABOVE SAID FIRST PLATE, SAID SECOND PLATE BEING WEIGHTED IN ORDER TO BRAKE THE THREAD. 